• Age≥ 18 years old;

• Patients with histologically or cytologically confirmed non-bone metastases stage IV NSCLC;

• EGFR, ALK, and ROS1 are all wild-type (for other driver genes, if there is no first-line approval for corresponding targeted therapy or if the patient refuses targeted therapy, these patients are allowed to be enrolled);

• first-line treatment with immune checkpoint inhibitors and clinical benefit (PFS ≥ 3 months);

• Have measurable lesions (according to RECIST 1.1 criteria, the long diameter of CT scan of tumor lesions is ≥10mm, the short diameter of CT scan of lymph node lesions is ≥15mm, and the thickness of the scanning layer is not more than 5mm, and the measurable lesions have not received local treatment such as radiotherapy and cryotherapy);

• ECOG PS: 0-2 points;

• Estimated survival time≥ 3 months;

• Adequate hematologic function, defined as absolute neutrophil count ≥1.5×109/L, platelet count ≥ 80×109/L, hemoglobin ≥ 90g/L (no history of blood transfusion within 7 days, not corrected with G-CSF and other hematopoietic stimulating factors);

• adequate liver function, defined as total bilirubin levels ≤1.5 times the upper limit of normal (ULN) and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels ≤ 2.5 times ULN, or for patients with liver metastases, AST and ALT levels ≤ 5 times ULN;

⁃ adequate renal function, defined as creatinine clearance ≥50ml/min (Cockcroft-Gault formula);

⁃ Adequate coagulation function, defined as the international normalized ratio (INR) or prothrombin time (PT) ≤ 1.5 times ULN;

⁃ For female subjects of childbearing age, a negative urine or serum pregnancy test should be performed within 3 days prior to receiving the first dose of study drug, and if the urine pregnancy test result cannot be confirmed as negative, a blood pregnancy test is required;

⁃ If there is a risk of conception, male and female patients need to use highly effective contraception (i.e., a method with a failure rate of less than 1% per year) and continue until at least 180 days after stopping the trial treatment (Note: abstinence can be accepted as a contraceptive method if abstinence is the subject's usual lifestyle and preferred contraceptive method);

⁃ Subjects voluntarily joined this study, signed a written informed consent form before the implementation of any trial-related procedures, had good compliance, and cooperated with follow-up.